Plastic clothespin



Oct. 21, 1947. M. MACCAFERRI' 2,429,557

PLASTIC CLOTHESPIN Filed Jan. '51, 1945 W3; ,llffffff INVENTOR Mar/'0 Maccaferri K @5071 ATTORNEY Patented ct. 21 1947 UNITED STATES PATENT OFFICE PLASTIC CLOTHESPIN Mario Maccaferri, New York, N. Y.

Application January 31, 1945, Serial No. 575,452

1 Claim. 1

This invention relates to clothes pins of plastic material, and has for its object to provide a pin which on the one hand will resist strains and stresses tending to break it, and on the other hand, hold the clothes on the line in a tight manner, preventing disengagement of the pin from the line.

For this purpose, the improved pin of plastic is provided at its handle portion with strengthening ribs, at right angles to each other, certain of such ribs terminating at an inverted U shaped portion at the top of the clamping members; and other ribs extending the entire length of the pin, fillets being provided to prevent a twisting action. Also, the runway for the line is so arranged as to provide easy entrance of the line between the clamping curves, but to provide a resisting exit by a resisting curve against the exit of the line. Such easy entrance and resistance curves, in mirror reverse, may be one pair, or a plurality of successive parts. The clamping members act as calculated springs instead of rigid levers, and thus they present no weak points. No matter what the thickness of the clothes and line the conditions are the same, when a plurality of curves in pairs are used. The runway is smooth throughout and thus does not injure the clothes.

The invention will be more fully described hereinafter, embodiments thereof shown in the drawings, and the invention will be finally pointed out in the claim.

In the accompanying drawings,

Fig. 1 is a front view out the improved pin of plastic;

Fig. 2 is a side view;

Fig. 3 is a horizontal section on line 33 of Fig. 1;

Fig. 4 is a horizontal section on line 4-4 of Fig. 1;

Figs. 5 to 8 are diagrammatic drawings of the operation of the pin;

Figs. 9 and, 10 are diagrammatic drawings of modified 'forms; and

Fig. 11 is a diagrammatic'drawing showing the manner of constructing the curve.

Similar characters of reference indicate corresponding parts throughout the various figures.

Referring to the drawings, the improved clothes pin is made of one piece of molded plastic material, preferably made by the injection method with known materials. It has a handle portion l0 and a gripping portion H. The handle portion It! is made of cross shape with ribs l2 and 14 at right angles to each other. The ribs [2 extend laterally of the handle portion and from the tip of the handle portion to near the lower ends of the gripping portion H. The ribs I4 are at right angles to the ribs I2, and extend from the tip of the handle portion Ill to the 2 gripping portion H, where they are merged integrally with an inverted U bend of the gripping portion H.

The ribs l2 and I4 have fillets l5a which strengthen the ribs and prevent a twisting action of the gripping members. The inverted U at 28 is either semi-circular or oval (parabolic).

Within the two clamps of the gripping portion H, a runway for the clothes line is provided of the shape shown in Fig. 1. A horizontal section (Fig. 4) taken on line 4-4 of Fig. 1 shows the inner surfaces having fiat plane, with curved portions at spaced intervals.

Referring to the diagrammatic views shown in Figs. 5 to 8 which show the inner contour of the runway of Fig. 1, the open end of the gripping portion I (Fig. 1) is flared from the tip I9, to permit ready entrance of the clothes on the cable, rope, or line. A curve 22 is provided which terminates at 20. A space 22a is provided for the entrance of the line 2|. This space has a gentle incline to a peak and then is convex to 20, which convex portion provides an obstruction to the outward movement of the line. This curve 22 then merges smoothly into a first fiat gripping part 23 which is substantially straight and parallel with the axis 24 of the pin, as shown in Fig. 1. A second curve like the one described merges into the upper end of the part 23 which curve has an entrance flare 25 and its upper convex end 25 merges smoothly into a straight line part 21 which is substantially parallel with the axis 24 of the pin, as shown in Fig. 1. The upper end of the straight part 21, merges into one end of a semi-circular part 28, the center of curvature of which is at 29. In the foregoing description, only one clamp has been described. The opposite clamp is in mirror reverse. This part 28 may be oval or formed with parabolic sides. As the end 30 (Fig. 5) of this curve is moved outwardly away from the center or" curvature, the inherent resilient forces provide reaction forces tending to return the curved part 28 to its initial or original shape, as shown in Fig. 5. The arrows 3| in Fig. 5 show the relative strength of these forces. In Fig. 7, wherein the clamps are spread further apart, these forces are larger, as shown by the longer arrows 32.

In Fig. 5, the line 2! is somewhat compressed as it passes between the peaks of the curves, and likewise in Fig. '7. In Figures 6 and 8, the line expands almost to its initial condition. The line may be cordage or steel. In Figs. 6 and 8, the line is held by the clamping action of the straight parts 23 and 21, respectively, against the line and against the convex curves 40, and is thus prevented from disengagement by reason of the convex curved portion 50, which opposes the outward movement of the line. The entrance of the line is desired to be with a gentle and easy movement, whereas the exit of the line should meet with opposition to resist the action of the return movement upon the clothes. The space between the lower curves is smaller than between the higher curves, as shown in Fig. 1, and in Figs. 9 and 10.

The inherent resilient action of the semi-circular part 28 is strengthened by the front and rear ribs l2, which at their lower ends merge into and are integral with said part-as clearly shown in Figs. 1 and 2. A further and important function of these front and rear structural mem-' bers or ribs combined with the lateral ribs is that the clamps of the gripping portion are so strengthened that a breakage of the clamps at or near the U 28 is obviated: 7

One objection to the use of plastic pins is that breakage readily results, by one or the other clamp breaking ofi, or the handle portion splitting. The structuralstrengthening ribs I2, at the front and rear, merging into the curved or semi-circular part 28, where a heavy reinforcement is provided as at 35, prevents this. Furthermore, the ease of entrance dueto the line riding on a soft curve, instead.of an' abrupt curve, subjects the clamps to an even action instead of to an abrupt action much like a. leaf spring. The clamps do not act as a rigid lever pivoting at 28, but give slightly along their length.

In Fig. 5, the angle of' the tangent line from center 29 to the peak of lower inner curve in idle position as in Fig. 1, is shown by 31, and the line 38 being the same tangent line in working position. The space 36 is increased to space 38a. In Fig. 7, the tangent line 39 is. the normal or idle position line, tangent to the upper curve, and the line is the tangent line changed to working position, the angle M resulting. The axis 24 is shown in Figs. 1, 5 and 7. After the line 2! has passed'the p'e'aksof the curves, the clamps again approach each other, as shown in Figs. 6 and 8.

The cross at the handle portion givesa good grip to the pin.

In Fig. 5 two successive flares and convex curves are shown at each side of the median line 24. Figures 6, 7 and 8 show the same structure in diiferent positions. In Fig. 9 three successive flares and convex curves are shown and in Fig. 10, four such cooperating. parts are shown.

It will be noted that in Fig. 9 the spaces 29a, 20b and 280, and in Fig. 10 the-spaces 29a, 29b, c and 29d between the peaks of the opposed curves are wider from the lower to the higher curves. The plurality of pairs of opposedcurves adapt the clothes pin to different sized thicknesses of clothes and line.

Figure 11 is a diagrammatic drawing, showing the manner of constructing the curve. A horizontal 35 is drawn perpendicular to the axis 24; and divided into three parts, starting at theaxis Z4, and extending to the right thereof. The first division point 63 is used as a center, and an arc is drawn above the horizontal 35 corresponding to an angle of about 40, the radius of curvature being somewhat less than saidthird division to allow for a space 29a, adapted to the thickness of the line. The end point 3! is used as a center of curvature, and an arc is drawn as a continua tion of the first arc and corresponding to an angle of about 40. The resulting total curve is part of an inverted raindrop indicated by 83 and shown in dotted line. Thus a streamline is Number 4 formed by the continuous arc in full lines, giving the least resistance to the movement of a body gliding thereon.

Another important feature is the merging of the U-shaped portion with the rib which is a right angle to the plane of the U-shaped portion, which cooperation of parts is to prevent the breaking of the pin, and gives the clamping members a spring like efiect, contrary to a rigid lever effect.

No matter what thickness is clamped, the same condition is: obtained. In all cases, it is easy to place on the clothes line; it can be used on heavier lines or lighter lines, and yet retain a good strong grip. The curved and straight planes of the runway are smooth and do not destroy or tear the clothes, or damage the-most delicate of materials-silk, rayon,- etc., and do not catch, tear or snag. The right angled ribs of the handle portion enable the user to get the pin into the proper position, and enablethe positioning of the pin even with wet fingers, and when the pins are taken off they do not slip from the fingers. The fillets-of the ribsprevent a twisting of the clamps. The clamps act'as a spring instead of a rigid lever, and have no weak spot.

I have described several forms of my invention, but obviously various changes may be made in the details disclosed without departing from the spirit of the invention as set out in the following claim.

I claim;

A plastic clothes pin, comprising a handle portion and a gripping portion, the handle portion having pairs of intersecting ribs throughout its length, said pairs of ribs being at right angles to each other, the gripping portion having. a U-shaped curve flanged portion forming an extension of one pair of said ribs, the said ribs merging into the bend of the U, the other pair of ribs extending along the exterior of the flanged portion substantially the length of the same and at right angles thereto, said flanged portion having an interior planular runway, said runway having a contour in mirror reverse in respect to the axis of the pin, and consisting of a series of opposed spaced curved portions, each having an easy entrance flow andla-resisting outlet flow, the entrance flow having a. larger radius of curvature than the outlet fiow, and having a fiat plane portion parallel with the axis of the pin disposed between said curved portions.

MARIO MACCAFERRI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS FOREIGN PATENTS- Country Date Canada July 11, 1916 Switzerland lit/lay 13, 1911 Number 

